I think most of us can agree that higher ranked players have an easier time adjusting to certain balance changes, but in the end the game has to be playable for the majority, not some top 1%, and this is where OPs data is quite fascinating - even though i doubt such a huge difference in win ratios.
just my 2 cents
OP data are wrong or false.
And this is not how you balance a game, ask Blizzard about SC2.
If you listen Germans they only have craps units, blob of volks/Panzerfusilier with vet5, panther, stuka, KT, Panzer II yea it's so bad... jeez